Acoustical plaster



106. COMPOSITIONS,

COATING OB PLASTIC This invention relates to a composition ofmatter, forexample, plasters and the like, and is more particularly concerned with such materials which possess the properties of heat insulation, 5,55 sound insulation or absorption, light weight, easy workability, uniform texture, and controllable rates of drying. It also relates to such materials which can berendered highly resistant to'heat;

can be controlled as to hardness within certain a..continuation in part of my co-pending application Serial No. 289,634, filed June 30, 1928.

Material embodying the present invention may) beivariously used. For example, it may be employed as a wall covering and applieddirectly. to agnetal surface such as structural steel membersorto lath or wood or metal. when so em sac adherence by reason of the fairly soft open tex.-; ture of the material. -;;..A typical composition of material embodying the present invention for. the just described purposes isqas follows:;:.---; 1. Percent Rock wool -..from about 44%. to about 53 Diatomaceous earth from about 37% to about 50 Lime 1 (bydrated. or. ,t air slacked) from about 6% to about 8 our from about 1% to about 5 By terinfRock wool which'appears'above, I mean any mineral wool having a critical point about 1500 F., at which it breaks down. Materials such as asbestos have a critical point of about 1400 F., that is, at this temperature. they break down and become of practically no use. asja fireproofing material. Since other materials, which are unable to stand temperatures in excess of about 1500" F., without breaking down, are becoming of little value as fireproofing, they are for the purpose of this invention, with asbestos, excluded from the scope hereof. Accordingly the term Rock wool as used in this application is intended to include any and all wools of a mineral nature providing a critical point above about,1500 F. Preferablythe materials comprehended by the term Rock wool, as used herein, are of a fibrous forirtwith the fibers preferably t 11,968,489 t ,.f A ti rm r f Seymour M. lenkim l akewood, Ohio I N6 Drawing. apiiusubn s, 1931, Serial I. v No.508,497 Renewed September 24, 1932 n ranges and can be colored. This application is] afinish. plaster coat may be applied with good not exceeding length and containinginot ,morethan 12% of shot-like particles, Although materials of various chemical composition maybe used as Rock wool such materials are usually some form of silicates where the silicate formsa' material'partof the composition. One typical t 1 Rock woolfcomposition satisfactory for Ipracticing the present invention is the. present day commercial product known in the trade as *Gimco' Rock wool and having a chemical analysis" approximately as follows:-

present but if present in very smallamounts under 1%.

4.1: -T This material may be prepared for use with this invention by various processes. One ex-' ample of such a process is by steps including: melting the rockpdrawing the melted rock in fibres; and annealing the fibres in oil. I

' Diatomaceous earth is well known commer- Examiner It is preferred that sulphur should not be cating air voids and which for this reason are 5 well adapted for sound absorbing, fireproofing uses. The flour specified may be flour mill sweepings or low grade flour, gluten or any suitable paste or adhesive; a The lime may vary on ither side of the range named but the weight of the composition will vary correspondingly. A r

The rock wool, earth, flour and lime may be mixed dry and then mixed with sufficient water just prior to spreading on the supporting means to form a wall or wall covering. The mix dries out leaving a resilient. soft, coherent, adherent, expansible and contractible mass having a rough surface to which a surface coat of plaster or the like or paint adheres closely. The material is gue QB m [06. COMPOSITIONS,

bTOSS sound to a marked degree and where the higher degree of sound deadening is desired the material should be exposed, that is, not covered with a surface coat such as plaster. For certain purposes the material may be prepared in the form of blocks and laid in the usual manner of laying block materials.

This material increases in strength from about 20% to about 26% when wet after setting. It is thus well adapted for fireproofing because it not only does not burn but exhibits greater adherent surface. of a fire, and has less tendency to flake Qfl, crack a which it covers" strength when wet as is certain to occur in case or otherwise expose the structure incaseofafire.

When the rate of drying or set is to be prolonged a retarder may be added to the foregoing typical composition. About i-poundof caust soda or 5 pounds of laundry starch, or botE may e added to each 10 p s o the foregoing composition for this purpose. I The retarder is preferably first dissolved in hot .water and added as a solution; When the drying or set is to be hastened an ggcelerator may be used. About 1 pound of a n i monium su phate, common salt or otherv sub! stance g re ardin properties corresponding to the sulphate may be utilized for this pin-s pose and added to each 100 pounds .of the typical Composition. .fff. .a: 13m I? I'.... When the foregoing typical composition is used without a covering or finish plaster or the like it may be variously colored. For such work'a glue like property is preferably imparted to the 00mposition. One satisfactory method of accom plishing this is to add about 5 pounds of laundry starch and about 1' pound of austic soda both sso ved in hot water to each 105 pounds of the. typical composition. After the material has been spread for a day or two a'pigment may be applied to the surface of the material. By varying the force with which the pigment is blown against the material, different degrees of unevenness in the surface of the material may be obtained. The pigment is retained by theme.- terial into which it may even penetrate a small distance and after the material dries the pig ment can be removed only with difiieulty and hence is substantially permanent.----'- 5 Where fire resisting properties are mainly desired the foregoing typical composition may have added to each 100 pounds of it, about'l pound of hydrated or air slacked lime about 3 pounds of Hour or similar sticking material, about 5 pounds of Portland cement and from about 2 pounds to about 10 poun of porous material such as blast furnace sl screenin s. This composition may be applied to the strum ture to be fireproofed and after drying 'may receive a surface coat of the typical composition or of plaster or both, if desired. It 'is only necessary to scratch the hard glossy surface of the fireproofing material to provide the necessary anchorage for the surface coat. This fireproof material weighs from about to about pounds per cubic foot, hasfsomewhat less ability to absorb sound than the typical composition; and shows an increase of about'20% in strength when wet' after setting-.' Little or no heat is necessary for drying and setting. any of; the foregoing materials beyond the, heat ordinarily required for ordinary plaster. The fireproofingmaterial last mentioned is suitable foruse in floor and roof construction where it may be applied to expanded lath or the neierence walls or attics where it may be applied dry and then sprinkled with water to form a non-dusting I have thus described my invention so that others may be enabled to practice the same and not for the purpose of limiting it to the details set forth. The scope of my invention is defined in what is claimed. Iclaimz v ,1. A. cellular wall covering containing Rock wool," diatomaceous earth, lime and cereal flour and characterized-by .being spongy, expans'ible and contractible and weighing approximately 30 pounds per cubic foot. 2. A cellular sound absorbingwall forming material containing between 44% and about 53% of Rock wool", between about37% and about of diatomaceous earth, between about 5% vand about 8% of lime and between about 1% and about 5% adhesive. 1 I I i' 7 3. A cellular sound absorbing wall forming material containing between about44% and about 53% of .Rock wool", between about 87% and about 50% of diatomaceous earth, between about 6% and about 8%0! lime and between about 1% and about 5% of cereal fiour. 7*-

4. Acellular material containing principally Rock woo and diatomaceous earth, small amounts of lime and flour-and a hardening rc-i tarderahsf A 5. A cellular material containing principally Rock "wool" and diatomaceous earth, small amounts of lime and fiour and a hardening retarder in the form of caustic sodaC- 6.1 cellular material containing principally Rock wool" and diatomaceous earth, small amounts of lime and flour and a harde accelerator. .-"l. A cellular material containing principally Rock 'wool and diatomaceous earth, small amounts of lime and flour and a hardening accelerator in the form of ammonium sulfate. 5 8. A cellular material containing principally .Rock wool" and diatomaceous earth, small amounts of lime and fiour, a hardening retarder', and a pigment on the surface thereof. a Yi'if 9.'A cellular material 1 containing principa :Rock wool and diatomaceous earth.- Small amounts of lime and flour, a hardening retarder inthe form of caustic soda and a. pigment on the surfacethereof. ..1 IL 10. A. cellular material cl ntainin Principally "Rock wooland diatomaceous earth. small amounts of lime. and flour and a pi ment on the surface thereof. y J- 11. A cellular material containing principally Rock wool and diatomaceous earth.' small amounts of lime and flour, an adhesive and a pigment on the surfacethereof.

j; 12 A cellular sound absorbing wall "forming material containing between about. 44% and about 53% of fRock wool, a slightlyless percentage of diatomaceous earth, 'sumcient'lime to provide a bond and adhesive to thelextent of about 5%." ",2; -13. A cellular sound absorbing wall forming examiner terial containing between about 44% and about 53% of Rock wool" a slightly less percentage of diatomaceous earth, sumcient lime to provide a bond and adhesive sufiicient to render the material adherent and easily workable.

14. A cellular wall material containing principally Rock wool and diatomaceous earth, small amounts oi lime and flour, and small amounts of Portland cement and blast furnace slag'screen mas o I 15. A cellular material containing principally "Rock wool and dlatomaceous earth, small 1,9as,4se

amounts of a suitable binder and a hardening retarder.

a 16. A cellular sound absorbing wall forming material contalning between 44% and about 53% JRock wool, a slightly less percentage ,of diatomaceous earth,.suitable binding and adhesive material to the extent of about 5%.;

amounts or a suitable binder and small amounts pally Rock wool and diatomaceous earth, small j of Portland cement and blast furnace slag screen,- 7

88$ SEYMOUR M. JENKINS. 

